Adding an additional Value in a DICOM Image using dicomwrite

Hello Community,

I'm trying to generate a DICOM File from data I've stored as an uint8 with the size 1000x1000. It' s called 'image'. Then I'm adding some information for the header as shown in the code. While InstanceNumber, SeriesInstanceUID and StudyInstanceUID are saved to my file, PatientPosition is not. I came up with the idea that this is maybe not the case because it's not one of the 'standard' or necessary information. Now I found out the ID of this Metafield from here: https://dicom.innolitics.com/ciods/basic-voice-audio/general-series/00185100, but I don't know how to save the value with this method.

uid1 = dicomuid;
uid2 = dicomuid;
% [...]
image=im2uint8(data);
info.InstanceNumber=6666;
info.SeriesInstanceUID = uid1;
info.StudyInstanceUID = uid2;
info.PatientPosition = 'HFS';
dicomwrite(image, ['F:\test.dcm'], info)

My 'work' is based on the following question: https://de.mathworks.com/matlabcentral/answers/479922-generate-dicom-file-sequence-from-matlab

For checking if my save was successfull I'm using

dicominfo('test.dcm')